/*
 * Copyright (c) 2019 Spotify AB.
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package com.spotify.heroic.aggregation

import com.fasterxml.jackson.annotation.JsonValue
import com.fasterxml.jackson.databind.annotation.JsonDeserialize
import java.util.*

/**
 * Backwards compatibility from the dark ages, where group aggregations 'each' field took a list.
 * <p>
 * XXX: remove when deprecated.
 *
 * @author udoprog
 */
@JsonDeserialize(using = AggregationOrListDeserializer::class)
data class AggregationOrList(val aggregation: Optional<Aggregation>) {
    @JsonValue
    fun toAggregation() = aggregation

    companion object {
        @JvmStatic
        fun fromAggregation(aggregation: Aggregation) =
            AggregationOrList(Optional.of(aggregation))
    }
}
